Interfacial Coupling Effects of the Quaternary Heterojunction Composite for Enhanced Visible-Light Photocatalytic NO Purification

Economical and efficient photocatalytic nitrogen oxide (NOx) purification is regarded as one of the most promising ways to address air pollution. However, the performance of photocatalytic NOx purification is still limited by the light absorption efficiency and the carrier separation efficiency of photocatalysts. Herein, a quaternary heterojunction composite (Bi2O3/Bi4O5Br2/AgBr/Ag3PO4, abbreviated as BBAA) was constructed by the chemical precipitation method. The established efficient charge transfer channel at the multicomponent interfacial coupling effects of BBAA can promote the rapid separation of photogenerated charges (e(-)/h(+)). The BBAA exhibited superior visible-light absorption capacity and light utilization, resulting in a stable NO removal ratio of over 50% (the maximum ratio is 57.86%) with a rare toxic byproduct (NO2) during the photocatalytic continuous NO flow purification. The in situ diffuse reflectance infrared Fourier transform spectroscopy analysis demonstrated that the composites (BBAA) with more reactive radicals enabled the deep oxidation of NO by the synergistic effect between the multicomponent and structure. This work provides a new idea for the rational design, preparation, and application of highly efficient composite photocatalysts for solar energy utilization.